INTRACOLON COOLING INCREASES SURVIVAL RATE IN THE RAT MODEL OF LETHAL HEMORRHAGE.

Background

The objective of this study was to investigate whether transrectal intracolon (TRIC) cooling can prolong the survival duration in a rat hemorrhagic shock (HS) model.

Methods

A lethal HS was induced by bleeding 47% of the total blood volume. A TRIC device was placed into the colon to maintain the intracolon temperature either at 37°C (TRIC37) or at 10°C (TRIC10) post-HS. In the surface cooling (SC) rats, the body temperatures were maintained at the same level as the esophageal temperature of the TRIC10 rats. A separated group of TRIC10 rats were resuscitated (Res) at 90 min post-HS. A total of six groups were as follows: (i) Sham TRIC37 (n = 5), (ii) Sham TRIC10 (n = 5), (iii) HS TRIC37 (n = 5), (iv) HS TRIC10 (n = 6), (v) HS SC (n = 6), and (vi) HS TRIC10 + Res (n = 6).

Results

An average post-HS survival time was 18.4 ± 9.4 min in HS TRIC37 and 82 ± 27.82 min in the HS SC group. In striking contrast, the HS TRIC10 group exhibited an average survival time of 150.2 ± 66.43 min. The post-HS blood potassium level rose significantly in the HS TRIC37 and HS SC, whereas it remained unchanged in the TRIC10 groups. Post-HS intestinal damage occurred in HS TRIC37 and HS SC groups but virtually absent in HS TRIC10 groups. After resuscitation at 90 min post-HS, all HS TRIC10 rats were fully recovered from the lethal HS.

Conclusions

TRIC10 reversed the high blood potassium level, prevented the intestinal damage, and prolonged the survival duration by sixfold relative to normothermia and by twofold compared with SC post-HS. All TRIC10 rats were successfully resuscitated at 90 min post-HS.